Reforming of gaseous hydrocarbons



May 5, 1964 Original Filed Jan. 4, 1957 9, LOG MEAN RESIDENCE TIME, SEC.0 to 0 J. a. DWYER ETAL 3,132,010

REFORMING 0F GASEOUS HYDROCARBONS s sneets-snet 1 FIGQI RESIDENCE TIMEIN.METHANE REFORMING (CATALYST or TABLE 1:: 6% cu m DRY EFFLUENT OUTLETPRESSURE, PSIG INVENTORS JOHN B. DWYER JOSEPH w. JEWELL WILLIAM B.JOHNSON HENRY c. McGRATH LOUIS c. RUBIN 2 ATTOR ZEYS 9..LOG MEANRESIDENCE TIME, SEC.

y 1964 :1 J. B. DWY'ER ETAL REFORMING OF GASEOUS HYDROCARBONS PIC-3.2

RESIDENCE TIME IN METHANE REFORMING (CATALYST OF TABLE 1:.) 6% on m DRYEFFLUENT OUTLET PRESSURE, PSIG INVENTORS JOHN B. owvaa JOSEPH W.JEWELLWILLIAM B.JOHNSON HENRY c. McGRATH LOUIS c. RUBIN Z AT;ORNEY$ UnitedStates Patent O 3,132,010 REFQRMING F GASEOUS HYDROCARBONS John B.Dwyer, Garden City, N.Y., Joseph W. Jewell,

New London, N.H., William B. Johnson, Peapack, and Henry G. McGrath,Union, NJ., and Louis C. Rubin, La Jolla, Caliii, assignors to Pullmanincorporated, a corporation of Delaware Continuation of appiication Ser.No. 632,599, Jan. 4, 1957. This application Nov. 8, 1962, Ser. No.236,776 8 Claims. ((Zl. 48-496) the reduction of iron oxide to producesponge iron. This application is a continuation-in-part of applicationSerial No. 33,572, filed January 27, 1953, now abandoned. Thisapplication is a continuation of application Serial No. 632,599, filedJanuary 4, 1957, now abandoned, which in turn is a continuation-in-partof application Serial No. 333,572, filed January 27, 1953.

Reforming of methane with steam to produce hydrogen and carbon monoxidehas been known for some time in the prior art. Normally, reforming intubular type furnaces has been carried out at atmospheric pressure andat space velocities not higher than about 200 or 300 volumes per hourper volume of catalyst. With conventional catalysts and conventionaltypes of reforming furnaces the above space velocities were consideredmaximum for the production of a gas which did not contain excessiveamounts of unconverted methane because of increasing pressure drop andconsequent higher pressure at the hot end of the tube. It has been thedesire for some time to achieve the reforming of methane to producehydrogen and carbon monoxide without excessive unconverted methane inthe product under higher pressures and higher space velocities. However,such conditions have not been achieved. Higher space velocities aredesirable because it means a higher conversion to hydrogen and carbonmonoxide per pound of metal tubing in the furnace thus decreasing thevery high cost of the furnace. It is further desirable to increase boththe pressure and space velocity in order to increase the capacity of thefurnace and thus reduce required catalyst inventory. Pressure operationsare particularly advantageous as the higher space velocities and muchgreater endothermic heat of reaction per tube results in greater heattransfer per unit tube surface area without any increase in metaltemperature. Pressure operations also decrease the cost of subsequentcompression, such as when using the hydrogen and carbon monoxide gasformed for the production of hydrocarbons by the Fischer-Tropschreaction under elevated pressures, or in ammonia synthesis, or synthesisof methanol or isobutanol.

It is an object of this invention to provide a method and apparatus forachieving higher space velocities and pressures for the reforming ofnormally gaseous hydrocarbons to hydrogen and carbon monoxide.

tubes is between about 3 and about 4 /2 inches.

Another object of this invention is to decrease the cost of thereforming furnace.

Yet another object is to produce a gas rich in-hydrogen and carbonmonoxide with a low concentration of unconverted feed gas.

Still another object of this invention is to provide a more efficientprocess for the conversion of methane to hydrogen and carbon monoxide.

Yet a further object of this invention is'to provide a method fordecreasing the cost of subsequent compression of the reforming gases foruse in the synthesis of hydrocarbons under elevated pressures.

Still another object is to provide a furnace design for the reforming ofmethane to hydrogen and carbon monoxide at high temperatures and highpressures.

Various other objects and advantages will become apparent to thoseskilled in the art from the accompanying description and disclosure.

According to this invention, hydrocarbons, such as methane, ethane,propane, butane, natural gas, liquefied petroleum gas, or naphtha arereformed'with steam, or steam andcarbon dioxide or carbon dioxide alonein a suitable reformingfurnace at an outlet temperature between about1350" F. and about 1700 F., preferably above 1450" F., at an inletpressure above 25 pounds per square inch. The tubes in the furnacecontain a reforming catalyst through which the hydrocarbon and steamand/ or carbon dioxide are passed are at least 2 /2 inches in diameter(O.D.) and not more than 5 inches in diameter (O.D.). Preferably theoutside diameter of the The maximum tube metal temperature should not bein excess of that which the tubes can safely withstand at the pressureemployed and" is usually between about 1600 F. and about 1800" F.depending, of course, upon the type of metal used for the tube. For mostefficient operations, the pressure is maintained above 50, andpreferably between about and about 150, pounds per square inch gage andthe outlet temperature is maintained between about 1350 F. and about1700" F., preferably between about 1450 F. and about 1600 F., with anickel oxide catalyst.

The catalyst of this invention is preferably a nickel oxide supportedcatalyst having a diameter between about A" and about /2" in the'form ofspheres or extruded pellets between about A" and about /2" in length.High space velocities can be used, particularly when such cata lyst ismodified with about 15 to 25 weight percent calcium oxide, preferablybetween about 21 and about 23 weight percent and/or magnesium oxide inan amount between about 5 and about 15 Weight percent. The support forthe catalyst may be synthetic or naturally occurring and the modifiersmay be added or originally present in the support. Other catalysts ofhigh activity may be employed in this invention without departing fromthe scope thereof.

The ratio ofsteam and/or carbon dioxide to methane equivalent ismaintained between about 1 and about 3. A suitable mol ratio of about2.1 to about 2.6 has been found satisfactory. Reforming with steamalone, the ratio of steam to methane equivalent should be at least 1.8in order to prevent excess carbon formation; with CO present this valuemay be lower. In employing the present invention in a synthesis process,approximately pertimes to obtain the same effluent gas composition.

, 3 cent carbon utilization is realized by recycling carbon dioxide fromthe synthesis reactor.

In order to achieve maximum efiiciency at high space velocities and highpressures preheating the methane steam reactants to a temperature above400 F. and not higher than about 1250 F. is practiced. The preferredpreheating temperature is between about 800 F. and about 1150 F. foreconomical reasons of preheater construction. Under the preferredconditions of operation ordinarily not more than 6 mol percent methaneis found in the exit gases. In some instances and with some catalystsless than about 1 or 2 percent of methane is obtained in the efiiuentgases at the preferred conditions.

In accordance with this invention it has been found that higherpressures and consequent increased space velocities may be employed forproducing an effluent gas containing a comparable methane content thanwith conventional reforming processes known today. The present inventionpermits operations resulting in a closer approach to theoreticalequilibrium in the efliuent than heretofore realizable. Generally, aneffluent containing a relatively small amount of methane may be obtainedby operating in accordance with this invention at space velocities inexcess of 700 volumes of methane equivalent per hour per volume ofcatalyst in the tubes of the furnace. With highly active catalysts, alow methane content of the effluent gas is obtained with spacevelocities as high as 1000 to 2000 volumes of methane equivalent perhour per volume of catalyst. Of course, it is to be recognized that indetermining the allowable space velocity (outlet pressure) for anyparticular methane content of the efiiuent gas the theoreticalequilibrium as determined by feed composition and outlet temperaturemust be correlated against the attainable approach to equilibrium asdetermined by the residence time and the efllciency (or mean rate ofreaction) in the reaction zone. As an example of such a correlation,FIGURE 1 of the drawings shows curves for the various operatingconditions of the present invention with a moderately active catalyst toproduce not more than 6 mol percent methane in the dry efiiuent. Fromthese curves of FIGURE 1 for any given operating conditions the maximumresidence time may be determined to produce a maximum of 6 mol percentmethane in the efliuent. The relation of the various ope-ratingconditions to residence time and gas composition is readily evident fromthe curves of FIGURE 1. 'For any particular exit gas compositioncontaining less than 6 mol percent methane the residence time must becorrespondingly increased. Similarly, for higher permissable methane inthe exit gas the residence time may be correspondingly decreased. Thecurves of FIGURE 1 were based upon experimental runs made on amoderately active catalyst of the following approximate composition:

FIGURE 2 of the drawing contains similar curves to FIGURE 1 but is,however, based upon a more active catalyst. It is seen from the curvesof FIGURE 2 that the relationship of the various operating variables isthe same as that of FIGURE 1. The higher activity of the catalyst,however, permits the use of shorter residence Thus,

space velocities between 1200 and 1500 are suitable. The

composition of the catalyst employed in the runs made to determine thecurves of FIGURE 2 is shown below:

These curves were based upon an efliuent gas containing 6 mol percentmethane because such composition is typical of many gases requiredcontaining hydrogen and carbon monoxide. 6 mol percent methane is aboutthe maximum methane tolerable for producing hydrogen for use in suchprocesses as hydrogenation and Fischer-Tropsch. Thus when producing agas for such processes in which the maximum methane content is 6 molpercent the residence time must be maintained at least that determinedby FIGURES 1 and 2 for the respective catalysts.

The use of small tubes in the reforming furnace materiall y increasesthe surface area of the tube in comparison with the volume inside thetube. This increase in surface to volume ratio of the tubes permits acorresponding increase in the weight of reactants heated to the reactiontemperature without an increase in the outside tube metal temperature.This factor substantially decreases the cost of the furnace per unitWeight of reactants. Although smaller tubes are ordinarily moreexpensive than larger tubes, the increase in Weight throughputpermissible with smaller tubes more than ofisets this added expense ofthe smaller tubes within certain limits.

Increased Weight of reactants per volume of tube may be achieved byincrease in pressure. However, it was contemplated that an increase inpressure at the same tube temperature for a given outlet gas compositionwould result in rupture of the tube and failure of the furnace. Trialsat increased pressures above 50 pounds per square inch gauge at the samecalculated tube temperature (same furnace temperature) revealed that thehigher reaction rates per unit volume of catalyst (or per unit area ofthe containing tube) actually reduced rather than raised the outsidewall temperature of the tube because the endothermic heat of reactionper unit volume of catalyst was higher than had been expected fromcalculations. Contrary to previous practice and calculations, it is,therefore, possible in an indirect heat exchange tubular furnace to useoutlet tube temperatures above 1450 F. and as high as 1700 F. at outletpressures above 50 and as high as to 200 pounds per square inch gagewithout tube rupture.

Experimental operations have demonstrated that the mechanical-thermaldevelopment of the gas producing unit permits satisfactory operation atpressures substantially above atmospheric which results in better spaceefliciency and thus make it even more profitable to use what had beenpreviously considered uneconomic design. This increase in spaceefficiency had never been demonstrated prior to our experimentaloperation. The higher the outlet temperature at any given pressure, thelower the methane content of the effluent gas at equilibrium and themore favorable the compositions, both as to methane and carbon dioxidefor the subsequent uses cited.

No matter what improvement may be made in available below 3" O.D. arenot usually practical or feasible. bee cause the decrease inreactionlspace.and'increasein cost of tubes per unit'volume of reactantspace is not offset by increase in reactantrate (poundbasis) at.thesesmall '6 fold'for introducing methane and steam into' tubes 12.Tubes 12 are filled with catalyst indicated by numeral 14 and the gasespass downwardly through the'tubes in concurrent heat exchange with theburning gases and are diameters. 5 withdrawn through manifold 13. Asuitable furnace de- Residence time used in FIGURES 1 and 2 is detersignincludes a furnace height'of about 25 feet, a furnace mined by dividingthe length of the reactor by the-1og length. ofv about 20 feet. and.a.furnace. width of. about mean velocity of the steam-methane reactantsin the 5 /2 feet. Five tubes in three sections having an outsidereaction-tubecalculated by neglectingthevolume occupied diameter of 3 /2inches. are. used. for. the reforming secby the catlayst. Anysimilarmeasure of" mean volume tion. The reforming tubes are spaced. about 9inches may becorrelated in the same manner as in FIGURES apart.Restrictions in the form of 1 orifice plates (not I and- 2. Methaneequivalent is definedas the number shown) are used at the inlet of thetubes to provide sufof carbon atoms in the hydrocarbon feed mixture calficient pressure drop to insure uniform-flow of gases to culated asmethane. all tubes and consequent uniform heat load. The latter For abetterunderstanding of the present invention is-essential to controlthemaximum tube metal temperaand the type of furnace to be employed,reference will be time and a satisfactory mean composition of theefiluent; made to FIGURE 3' of the drawings which diagram- The followingtabulation ofdata (Table III) shows matically illustrates a furnacecross-section and in the results obtainedfor the reforming of propane inruns elevation; FIGURE 3 is an elevation view of the furnace 1 to 4 andmethane in runs 5- to-8 using acatalyst of while FIGURE 4 is aview takenalong line 4-4 of the compositionof'Tables I' andII and represents onlyFIGURE 3. Element 10 represents the casingof the a small portion of thedata used for determining the furnace which is constructed ofconventional refractory curves of FIGURES 1 and 2 The tab'ulationis inconmaterial. Combustible gases are introduced into the ventional formshowing the conditions of operations and furnace through inlets 15;These gases burnin the furresults in a furnace similar to the one shown.in the. drawnace between tubes 12- and are removed therefrom ing. Thereaction tubes of the runs of Table III were through longitudinalopenings 16 and passed through 2 1nch (I.D.) filled w1th about 11 andone half feet of manifolds 17 to a' conventional stack or heat recoveryth catalys Shown in Table II. The bulk density of equipment; Tubes 12are-spaced verticallyin the'furthe catalyst was about 71 pounds percubic fo t d nace across the furnace in a plurality of consecutivetubes. t e particle d sity Was about" 2.06 grams per cubic cen-Preferably at least 5 tubes-are employed for each sctlmeter. Thecatalyst was in the form of extruded pellets tion of tubing, as shown;Elementllrepresents a mani- X Table III Run N0 1 2- 3 4 5 6. 7 8

Length of period, hrs 8 8 4 2 8 4" 8 6 Reactor temp., F;-

Inlet 1,000 1,000 1,060 1,000 1,030 1,000 1,000 1, 000 Outlet 1,4501,380 1,400 1, 450 1,405 1, 495 1, 450 1, 455 Furnace:

, 105.6 113.1 108.5 212.9 208.5 329.0 405.0 Lbsi/hr 10.5 12.3 13.1 12.69.0 8.8 13.9 17.1 Steam (Orifice):

s.c.r.h 576 678 678 699 484 474 676' 853 Lb./hr 27.9 32.2 32.2 33.2 23.022.5 32.1. 40.5 Steam (Gale): 2

351,11 624 638 657 613 501 497 831 Lb./hr 30.0 30.3 31.2 29.1 23.8 23.639.5 Outlet Gas (Dry):

S.c.f.h- 908- 1,025 1,102 1,078 865 1,138 1,551 Lb./hr; 27.4 30.6 32.830.3. 22.8 22.2 29.8 38.1 Outlet Water: 4

S.e,f.h 301 282 285 232 273 236- 268 3.87 Lb./hr 14.3 13.4 13.5 11.013.0 11.2 12.7 18.4 Space Velocities: Inlet-v./hr./v 998 1,160 1,2431,194 780 764 1,205 1,483 Outlet-v./hr.lv 1,625 1,695 1,821 1,766 1,5381,516 1,894 2,611 Steam/equiv. GH4(Obs.) 2.1 2.1 2.0 2.1 2.3 2.3 2.1 2.1Steam/equiv. 01140510.) 2.3 2.0 1.9 1.9 2.4- 1.5 2.1 Outlet Gas, v01.percent (M. S.):

002;".- 10.0 8.8 8.5 5.5 7.3 7.0 6.2 6.2 16.8 18.0 18. 9 21.3 15.8 16.217.7 1 15:9 69.2 67.7 68.0 68.8 72. 7" 74.1 71.9 a 72.8 3.2 4.1 3.4 3.41.7 0.9 3.0 4.0 0.8 1.4 1.2 1.0 2.5 1.8- 1.2 1.1 11.29 11.32 11.27 10.6610. 06 9.75 9.94 9.30 4.1 3.8 3.6 3.2 4.6 4.6 41 4:6 060- 0.49 0.450.26' 0.46 0.43 0.35 0.39 Conversions:

Percent CH4- OO1; 33.3 28.5 27.6 18.2 29.4 1 29.1 21.4 23.8 Percent OHG0+OOq 89.4 86.7 89.0 88.8 93.2 96.3 89:6 84.7 MSa.terial)'Ba1an0es',percent (Basis Cale.

am I

Catalyst bed data-vol. cu; in, 0.273; weight-1b., 19.4:

1 Feed: Propane'in runs 1 to 4 and methane in runs 5 to 8. 2 Assuming100% hydrogen balance;

3 Assuming 100% carbon balance.

4 Includes: (1) Condensed water; (2) Water vapor in outlet gas (assumedsaturated at 14.7 p.s.l.a. and 75 Run No 1 2 3 Temp. in., Temp. out., FPress. in., p.s.1.g Press. out., p.s.i.g Stm. /CH4 equiv- Inletve1ocity, Lp.

Outlet velocity, f.p.s Residence time, sec Equiv. CH4 disappearance CH4in product H2200 ratio COaZCO ratio 1 Superficial velocity, based onempty tube.

2 Tube length, ft.

As an additional example of the gas reforming process of this invention,particularly as applied to an ammonia synthesis plant, a reformingfurnace was built having 315 tubes each having a 3 /2 inch outsidediameter and a .28 inch minimum wall thickness. The catalyst bed lengthwas 24 /2 feet.

The catalyst used contained the following ingredients: Si 26.3%, A1 029.2%, Fe O 0.7%, MG 24.8%, MgO 2.8% OaO 13.9%.

A natural gas feed having the following composition was used: CH 83.2mol percent, C H 9.5 mol percent, C H 3.8 mol percent, C H and C l-I 0.8mol percent, N 2.3 mol percent, CO 0.3 mol percent. The natural gas waspassed through the furnace at an outlet temperature of 1490 F. and anoutlet pressure of 125 p.s.i.g. Steam was fed to the furnace tubes at amol ratio to methane of 2.14. The space velocity was 840 volumes ofmethane equivalent per hour per volume of catalyst.

The efiiuent analysis on a mol basis was as follows: H 73%, N 1%, CH 6%,CO 12.2%, CO 7.8%.

As still another example of the reforming process of this invention,particularly as applied to a plant for the.

production of sponge iron by the reduction of iron ore, a furnace wasbuilt containing 14 tubes having an outside diameter of 4 /2 inches andan average wall thickness of 0.37 inch. The catalyst bed depth in eachtube was 20 feet 1 inch.

A natural gas feed having the following composition was used: OH; 95.5mol percent, C H 2.50 mol percent, C H 0.43 mol percent, 0 H 0.56 molpercent, N 0.56 mol percent, C0 0.10 mol percent.

The feed was passed through the furnace tubes containing the samecatalyst as described above with respect to FIGURE 2. The space velocitywas 1038 volumes of methane equivalent per hour per volume of catalyst;

Steam was fed at a steam to methane equivalent mol ratio of 1.9. Thetemperature at the tube outlet was 1495" F. and the pressure at the tubeoutlet was 54 8 pounds per square inch gage, maintaining the outlettemperature of said tubular reaction zone between about 1350 F. andabout 1700" F. by indirect heat exchange with a burning fuel andproducing an efiiuent gas in said single stage containing hydrogenwithout an excessive amount'of unconverted low boiling hydrocarbon.

2. A process for reforming a low boiling hydrocarbon to produce hydrogenand carbon monoxide which comprises passing a gaseous mixture comprisinga low boiling hydrocarbon and steam as substantially the sole reformingagent, said mixture having a steam to methane equivalent ratio ofbetween about 2.1:1 and about 2.621 and being preheated to a temperaturebetween about 400 F. and about 1200 F. through a multitubular re actionzone in a single stage in the presence of a nickel oxide supportedcatalyst having a diameter and length between about 4 inch and about /2inch at space velocities at standard conditions corresponding to atleast 700 volumes of methane equivalent per hour per volume of catalystat an outlet pressure of at least 50 pounds per square inch gage,maintaining the outlet temperature of said tubular reaction zone betweenabout 1350 F. and about 1700" F. by indirect heat exchange with theburning fuel which maintains the outside tube temperature of thereaction zone between about 1600 F. and about 1800 F. and producing anefiluent gas in said single stage containing hydrogen and carbonmonoxide and not more than about 6 mol percent unconverted low boilinghydrocarbon.

3. A process for reforming methane to produce hydrogen and carbonmonoxide which comprises passing methane preheated to a temperaturebetween about 800 F. and about 1150 F. and steam as substantially thesole reforming agent at'a steam to methane equivalent ratio of betweenabout 2.111 and about 2.6:1 through a multitubular reaction zone in asingle stage in the presence of a nickel oxide supported catalyst havinga diameter and length between about inch and about /2 inch at spacevelocities at standard conditions corresponding to at least 700 volumesof methane per hour per volume of catalyst at an outlet pressure betweenabout 65 and about 150 pounds per square inch gage, maintaining theoutlet temperature of said tubular reaction zone between about 1450 F.and about 1600 F. by indirect heat exchange with the burning fuel whichmaintains the outside tube temperature of the reaction zone betweenabout 16=00 F. and about 1800 F. and producing an efiluent gas in saidsingle stage containing hydrogen and H carbon monoxide and not more thanabout 6 mol percent unconverted methane.

4. A-process for reforming methane to produce hydrogen and carbonmonoxide which comprises passing steam as substantially the solereforming agent and The analysis of the effluent was as follows: C0 6.20t I.

mol percent, CO 14.80 mol percent, H 72.00 mol percent, CH 6.80 molpercent, N 0.20 mol percent.

Having described our invention, we claim:

to produce a product containing hydrogen which com- 4 66 1. A processfor reforming a low boiling hydrocarbon prises passing a preheatedmixture comprising a low boiling hydrocarbon and steam as substantiallythe sole methane pre-heated to a temperature between about 800 and about1150 F. in a'mol ratio of between about 2.121 and about 2.621 through amultitubular reaction zone in a single stage in the presence of a nickeloxide catalyst supported on a silica alumina support containing 1between about 15 and about 25 weight percent calcium oxide modifier atan outlet pressure of at least 5 0 pounds per square inch gage,maintaining the outlet temperature a of said tubular reaction zonebetween about 1350" F.

and about 1700 F. by indirect heat exchange with the burning fuel andproviding a residence time for the reactants corresponding to a spacevelocity of at least 700 volumes of methane per hour per volume ofcatalyst and producing an eflluent gas in said single stage containinghydrogen and carbon monoxide and not more than a 6 mol percentunconverted methane. 7 0.

p 5. The process of claim 4 in which the outlet temperature of thereaction zone is maintained between about 1450 F. and about 1600 F.

"6. The process of claim 4 in which the outlet pressure of the reactionzone is maintained between about and about pounds-per square inch gage.

7. A process for reforming methane to produce hydrogen and carbonmonoxide which comprises passing steam as substantially the solereforming agent and methane preheated to a temperature between about 800F. and about 1150 F. in a mol ratio of between about 2.1:1 and about2.6:1 through a multitubular reaction zone in a single stage in thepresence of a nickel oxide catalyst supported on a silica-aluminasupport at an outlet pressure of at least 50 pounds per square inchgage, maintaining the outlet temperature of said tubular reaction zonebetween about 1350 F. and about 1700 F. by indirect heat exchange withthe burning fuel and providing a residence time for the reactantscorresponding to a space velocity of at least 700 volumes of methane perhour per volume of catalyst and producing an eflluent gas in said singlestage containing hydrogen and carbon monoxide and not more than 6 molpercent unconverted methane.

8. In a process for reforming methane to produce hydrogen and carbonmonoxide in which steam as substantially the sole reforming agent andmethane are preheated to a temperature between about 800 F. and about1150 F. and are passed through a multitubular reaction zone in a singlestage in the presence of a nickel oxide supported catalyst and theoutlet temperature of said reaction zone is maintained between about1350 F. and about 1700 F. by indirect heat exchange with a burning fuel,the improvement which comprises maintaining the outlet pressure of saidreaction zone at least 50 pounds per square inch gage, maintaining asteam to methane mol ratio between about 2.1:1 and about 2.6:1 andproviding a residence time for the reactants corresponding to a spacevelocity of at least 700 volumes of methane per hour per volume ofcatalyst whereby an efiluent gas containing hydrogen and carbon monoxideand not more than 6 mol percent unconverted methane is produced in saidsingle stage.

Mayland Dec. 16, 1952 Roberts Ian. 13, 1953 ERNEST W, SWIDER AttestingOfficer UNITED STATES PATENT OFFICE CERTIFICATE. OF CORRECTION PatentNo,, 3,, 132,010 May 5 1964 John B. Dwyer et a1 It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 1, line 23 for "33 572" read 333 572 columns 5 and 6 Table III,under the heading Run Non 8" and opposite "Outlet waterz S.c,fQh for"3087" read 38? column 7 Table IV under the headings "2 and "3" strikeout all brackets; same Table IV under the heading "2" first item "1022"should appear opposite "inlet" instead of'as in the patent; same TableIV, under the heading 2% tenth item "7.5" should appear opposite "CH inproduct" instead of as in the patent,

Signed and sealed this 17th day of November 1964 (SEAL) Attest:

EDWARD J.- BRENNER Commissioner of Patents

1. A PROCESS FOR REFORMING A FLOW BOILING HYDROCARBON TO PRODUCE APRODUCT CONTAINING HYDROGEN WHICH COMPRISES PASSING A PREHEATED MIXTURECOMPRISING A LOW BOILING HYDROCARBON AND STEAM AS SUBSTANTIALY THE SOLEREFORMING AGENT AT A STEAM TO METHANE EQUIVALENT RATIO OF AT LEAST 1.8:1THROUGH A MULTITUBULAR REACTION ZONE IN A SINGLE STAGE IN THE PRESENCEOF A NICKEL OXIDE CATALYST AT SPACE VELOCITIES AT STANDARD CONDITIONSCORRESPONDING TO AT LEAST 700 VOLUMES OF METHANE EQUIVALENT PER HOUR PERVOLUME OF CATALYST AT AN OULET PRESSURE OF AT LEAST 50 POUNDS PER SQUAREINCH GAGE, MAINTAINING THE OUTLET TEMPERATURE OF SAID TUBULAR REACTIONZONE BETWEEN ABOUT 1350*F. AND ABOUT 1700*F. BY INDIRECT HEAT EXCHANGE